Built-in self-test for receiver

ABSTRACT

Representative implementations of devices and techniques provide a built-in self-test for a RF communication device. The communication device self-generates a test signal and processes the test signal through the communication device to determine an operational state of the communication device.

BACKGROUND

Generally, testing radio frequency (RF) communication devices is performed with the use of dedicated testing devices. For example, a first testing device may be used to generate an RF test signal, which may be injected into or transmitted to the communication device. A second testing device may be used to analyze resulting RF signals, as the test signal is processed by the communication device. These tests may be performed during production of the communication device as well as performed post-production.

In many cases, the use of such testing devices increases the costs and the testing time of the communication device. Dedicated testing devices may be purchased by users as well as manufacturers and service technicians to perform regularly scheduled tests or for quality control during production. Further, the use of dedicated testing devices may increase the complexity of regularly scheduled testing. For example, such tests cannot be performed when one or more of the testing devices are not available.

In recent years, communication devices have been integrated with or embedded within other consumer products (e.g., smartphones, tablet computing devices, utility meters, appliances, vehicles, etc.). In some cases, testing the communication devices while they are integrated or embedded can be problematic, based on limited accessibility to the portions of the communication device to be tested.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.

FIG. 1 is a block schematic of an example communication device RF portion, in which the techniques in accordance with the present disclosure may be implemented.

FIG. 2 is a block schematic of an example communication device, including an RF portion and a baseband portion, according to an implementation.

FIG. 3 is a graph showing a spectrum analysis of an example converted test signal, with amplitude modulation produced by on-off switching, according to an implementation.

FIG. 4 is a graph showing a spectrum analysis of an example converted test signal, with amplitude modulation produced by polarity switching, according to an implementation.

FIG. 5 is a graph showing a spectrum analysis of an example correlator output signal, associated with a converted test signal with amplitude modulation produced by on-off switching, according to an implementation.

FIG. 6 is a graph showing a spectrum analysis of an example correlator output signal, associated with a converted test signal with amplitude modulation produced by polarity switching, according to an implementation.

FIG. 7 is a flow diagram illustrating an example process of self-testing a communication device implemented as a system-on-chip (SoC), according to an implementation.

DETAILED DESCRIPTION Overview

Representative implementations of devices and techniques provide a built-in self-test for a radio frequency (RF) communication device. In an implementation, the RF communication device is implemented as a system-on-chip (SoC). In other words, the devices and techniques provide a radio frequency built-in self-test (RFBIST) for a RF communication device implemented as a SoC.

In various implementations, the communication device is arranged to self-generate a test signal and processes the test signal through the communication device to determine an operational state of the communication device. For example, the communication device is arranged to self-analyze the results of processing the test signal to determine whether the communication device passes or fails the self-test.

Various implementations, including techniques and devices, are discussed with reference to the figures. The disclosure illustrates the techniques and devices with reference to a RF receiver device. This is not intended to be limiting. The techniques and devices discussed may be applied to any of various communication device designs, circuits, and technologies, and remain within the scope of the disclosure.

Advantages of the disclosed techniques and devices are varied, and include (according to multiple implementations): 1) a test signal is self-generated by the communication device with a simple integer division and amplitude modulation (e.g., switching), and no extra signal generator is needed to test the communication device; 2) test results can be processed autonomously by the communication device, and no extra analyzer is needed to test the communication device; 3) the relationship between the modulation frequency (e.g., local oscillator frequency divided by an integer) and the intermediate frequency is relaxed and easy to achieve; 4) the test signal is based primarily on the fundamental frequency component, in contrast to a high order harmonic; and 5) enhanced test coverage is available, since a CDMA-type of signal can be self-generated, and processed in the baseband portion of the communication device. In summary, compared to other approaches, the disclosed RFBIST mechanism can reduce test time and cost, is more robust, and provides better test coverage. It is well suited to global navigational satellite system (GNSS) receiver implementations. Other advantages of the disclosed techniques may be apparent in the disclosure, based on the techniques and/or devices discussed.

In one implementation, a self-test apparatus may include a radio frequency (RF) phase-locked loop (PLL) device arranged to generate a local oscillator (LO) signal; a divider component arranged to divide a frequency of the LO signal by an integer value to produce a modulation frequency; and a modulation component arranged to modulate the LO signal at the modulation frequency to produce a test signal arranged to test a system-on-chip (SoC) communication device that includes the self-test apparatus.

The communication device may use a single PLL device, comprising the RF PLL device. The modulation component may further be arranged to receive a code signal and to spread the test signal based on the code signal. The code signal may comprise a Code Division Multiple Access (CDMA) code sequence and the spreaded test signal may comprise a CDMA-type test signal arranged to be processed by a baseband portion of a CDMA receiver.

The modulation component may further be arranged to modulate an amplitude the LO signal by switching the LO signal on and off or by switching a polarity of the LO signal at the modulation frequency.

The self-test apparatus may include a radio frequency built-in self-test (RFBIST) mechanism of a SoC Global Navigation Satellite System (GNSS) communication device.

In second implementation, a system-on-chip (SoC) implemented radio frequency (RF) communication device, may include a RF portion, including: a single radio frequency (RF) phase-locked loop (PLL) device arranged to generate a local oscillator (LO) signal; a divider component arranged to divide a frequency of the LO signal by an integer value to produce a modulation frequency; a modulation component arranged to modulate the LO signal at the modulation frequency to produce a test signal and to output the test signal, the test signal arranged to test the RF communication device; and a front end portion arranged to receive and to down-convert the test signal to form a converted test signal; and a baseband portion, including: one or more correlators arranged to analyze the converted test signal to determine an operational state of the RF communication device.

In the second implementation, the RF portion may further include one or more signal paths, each signal path including a band-pass filter tuned to one of a plurality of intermediate frequencies (IF) and an analog-to-digital converter (ADC) arranged to pass a digitized version of the converted test signal to the baseband portion.

In the second implementation, the plurality of intermediate frequencies comprise a plurality of global navigational satellite system (GNSS) intermediate frequencies, and wherein the converted test signal is arranged to pass through the band-pass filter of each of the one or more signal paths.

In the second implementation, the baseband portion may further include a plurality of code generators arranged to generate and output code sequences to the modulation component, the code sequences representing one or more global navigational satellite system (GNSS) spreading codes.

In the second implementation, the test signal may be based on a fundamental frequency of the RF communication device, the test signal comprising the LO signal with amplitude modulation, and spreaded by a code division multiple access (CDMA) code.

In the second implementation, the SoC-implemented RF communication device is arranged to autonomously self-generate the test signal at a receiver of the communication device, process the test signal through one or more receive signal paths of the RF communication device, and self-analyze test results of processing the test signal, to determine an operational state of the RF communication device.

In a third implementation, a method may include generating a radio frequency (RF) test signal at a receiver of a RF communication device having a single phase-locked loop (PLL) device;processing the test signal with the receiver to test an operational state of the RF communication device, the processing producing a resulting signal at the receiver; and analyzing the resulting signal at the receiver to determine the operational state of the RF communication device.

The third implementation may further include generating a local oscillator (LO) signal at the single PLL device of the RF communication device; dividing a frequency of the LO signal by an integer value to produce a modulation frequency; and modulating the LO signal at the modulation frequency to produce the test signal.

In the third implementation, the test signal has a center frequency at the frequency of the LO signal, and has first order frequency components at the frequency of the LO signal plus the modulation frequency and at the frequency of the LO signal less the modulation frequency.

The third implementation may further include spreading the test signal with a code sequence arranged to be decoded in a baseband portion of the receiver.

In the third implementation, the code sequence comprises a Code Division Multiple Access (CDMA) code sequence.

The third implementation may further include receiving and down converting the test signal to an intermediate frequency (IF) of the RF communication device at a front end portion of the receiver and band-pass filtering the converted test signal, the converted test signal passing a frequency band comprising the intermediate frequency plus the frequency of modulation and the intermediate frequency less the frequency of modulation.

The third implementation may further include autonomously self-testing the operational state of the RF communication device during production of the RF communication device and during post-production of the RF communication device, the RF communication device implemented with self-test functionality as a system on chip (SoC).

In the third implementation, the RF communication device may be arranged to receive and to process Global Navigation Satellite System (GNSS) signals.

Implementations are explained in more detail below using a plurality of examples. Although various implementations and examples are discussed here and below, further implementations and examples may be possible by combining the features and elements of individual implementations and examples.

Example Implementations

FIG. 1 is a block schematic of portion of an example radio frequency (RF) communication device 100. In various implementations, the communication device 100 is implemented as a system-on-chip (SoC). The disclosure and drawings discuss the communication device 100 in terms of a GNSS receiver, however, this is not intended as a limitation, and is for ease of discussion. Any reference to a “receiver” also applies to a communication device that includes a receiver or a receiver portion. The techniques and devices disclosed herein are applicable to various types of communication devices 100 of various circuits, technologies, and designs.

In various implementations, the communication device 100 may include a self-test apparatus, circuit, component, or the like, arranged to test the communication device 100. In an implementation, the SoC-implemented RF communication device 100 is arranged to autonomously self-generate a test signal at a receiver of the communication device 100, process the test signal through one or more receive signal paths of the RF communication device 100, and self-analyze test results of processing the test signal, to determine an operational state of the RF communication device 100.

A radio frequency (RF) portion 102 of the communication device 100 is illustrated in FIG. 1, in which the techniques in accordance with the present disclosure may be implemented. In various implementations, one or more components of the RF portion 102 may comprise dedicated self-test components, and one or more components of the RF portion 102 may comprise shared components, used for normal communication operation as well as for self-test operation.

In an implementation, as shown in FIG. 1, the RF portion 102 includes a RF phase-locked loop (PLL) device 104 arranged to generate a local oscillator (LO) signal f LO. In one implementation, the communication device 100 uses a single PLL device, comprising the RF PLL device 104. In other words, the one PLL device 104 may be used for generating a LO signal during regular operation of the communication device 100 (e.g., during processing of a received RF signal), and may also be used for generating a self-test signal during self-test operation of the communication device 100.

In an implementation, as shown in FIG. 1, the RF portion 102 includes a divider component 106 arranged to divide a frequency of the LO signal f_LO by an integer value (“N”) to produce a modulation frequency f MOD. In the implementation, the RF portion 102 also includes a modulation component 108 arranged to modulate the LO signal f_LO at the modulation frequency f_MOD, to produce a test signal. In the implementation, the test signal is arranged to test the SoC communication device 100, which includes the self-test apparatus (or components).

In various implementations, the modulation frequency f_MOD need not be equal to the intermediate frequency (IF) f_IF. In the implementations, f_MOD is arranged to be close to f_IF, such that the (converted) test signal can pass through the band-pass filter(s) of the receive signal path(s) of the communication device 100, with pass-band centered at f_IF. Accordingly, in the implementations, the f_IF need not be equal to an integer division of f_LO.

In an implementation, the modulation component 108 is arranged to modulate the amplitude the LO signal at the modulation frequency f_MOD. In one example, the modulation component 108 modulates the LO signal by switching the LO signal on and off at the modulation frequency. In another example, the modulation component 108 modulates the LO signal by switching a polarity (+ or −) of the LO signal at the modulation frequency. The modulated test signal then centers at f_LO, with first order frequency components at f_LO±f_MOD. In further examples, other modulation techniques may be used.

In one implementation, the communication device 100 comprises a Code Division Multiple Access (CDMA) receiver. In the implementation, the modulation component 108 is arranged to receive a code signal and to spread the modulated test signal based on the code signal. For example, the code signal may comprise a CDMA code sequence. In the implementation, the spreaded test signal comprises a CDMA-type test signal arranged to be processed by a baseband portion of the CDMA receiver. In various implementations, the code signal may originate internally or externally to the communication device 100.

In another example, the code signal may comprise one of various Global Navigation Satellite System (GNSS) codes. In the example, the test signal comprises a GNSS-type test signal arranged to be processed by a baseband portion of the CDMA receiver. In such an implementation, the self-test apparatus (or components) comprises a radio frequency built-in self-test (RFBIST) mechanism of a SoC Global Navigation Satellite System (GNSS) communication device.

In an implementation, since the test signal comprises the LO signal with amplitude modulation (and may be spreaded by a CDMA code), the test signal is based on a fundamental frequency (f_LO) of the communication device 100, rather than on one or more high order harmonics.

After modulating (and code spreading, in some implementations) the test signal, the modulation component 108 is arranged to output the test signal. For example, the modulation component 108 may output the test signal to a terminal, such as terminal 110. In an implementation, terminal 112 may represent a receive antenna for a receiver portion of the communication device 100. In the implementation, the test signal may be received at terminal 112, which is coupled to terminal 110.

In various implementations, the received test signal is processed in a receive signal path of the communication device 100. In some examples, the communication device 100 may be arranged with multiple receive signal paths, as shown in FIG. 1 (e.g., “Path A,” . . . ). For instance, each receive path may be arranged to receive and process a different GNSS signal, or the like.

In an implementation, the test signal is amplified and down-converted to IF by the front end 114. The test signal is also band-pass filtered at band-pass filter 116, with a center frequency at f_IF. The BPF 116 outputs the desired signal, e.g. at either +f_MOD or −f_MOD (when polarity switching amplitude modulation is used, for example). The test signal is sampled by an analog-to-digital converter (ADC) 118, and output to the baseband (BB) portion 202 of the communication device 100 for correlation.

FIG. 2 is a block schematic of an example communication device 100, including an RF portion 102 and a baseband portion 202, according to an implementation. In various implementations, the communication device 100, including the RF portion 102 and the baseband portion 202, may be implemented on a single integrated circuit chip, for example as a system-on-chip (SoC). In alternate implementations, the communication device 100 as SoC may be implemented with additional circuits or components, such as resistors, capacitors, antennas, or the like.

In the illustration of FIG. 2, the example implementation of a communication device 100 is arranged to receive and process both Global Positioning Satellite (GPS) signals and GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) (“GLO”) signals. For example, the GPS carrier frequency is 1575.42 MHz and the GLO signals are centered at 1602 MHz. In alternate implementations, the communication device 100 may be arranged to receive other signals, such as COMPASS (BeiDou Navigation Satellite System (“BDS”)), GALILEO, and other satellite signals or other CDMA signals. Further, the communication device 100 may be configured for more general, non-CDMA use by omitting code spreading modulation and de-modulation in test signal generation and processing. The example illustrated herein with regard to FIG. 2 (including the values indicated) is not intended to be limiting, and is for ease of discussion. In various implementations, other technologies, types, frequencies, codes, and associated values are within the scope of the disclosure.

In the example implementation, the f_LO is 1588.716 MHz. This frequency is divided by an integer value (120, for example) in the divider 106, resulting in f_MOD of 13.239 MHz. The f_LO is modulated using this f_MOD at the modulator 108, producing the test signal.

In an implementation, the baseband portion 202 includes one or more code generators arranged to generate and output code sequences to the modulation component 108. For example, the code sequences represent one or more GNSS spreading codes. Depending on the test mode, CDMA code based on GPS or GLO (for this example) is generated at the code generators 204 and applied to the test signal at the modulation stage 108. The test signal is spreaded using the applied code (either the GPS or GLO code), and output to the terminal 110. For example, after modulation, the test signal component at f_LO−f_MOD is used to test the GPS receive path, and the test signal component at f_LO+f_MOD is used to test the GLO receive path.

The spreaded test signal is received at the front end 114 from the terminal 112, to begin processing the test signal, and thus, testing the receive path(s) of the communication device 100. For example, the test signal is amplified and down-converted to IF frequencies by the front end 114. FIGS. 3 and 4 are example graphs showing a spectrum analysis of example converted GPS test signals (after processing by the front end 114), with amplitude modulation produced by on-off switching and by polarity switching, respectively, according to an implementation.

In an implementation, the RF portion 102 includes one or more signal paths, each signal path including a band-pass filter 116 tuned to one of a plurality of intermediate frequencies (IF) and an analog-to-digital converter (ADC) 118 arranged to pass a digitized version of the converted test signal to the baseband portion 202. In the implementation, the intermediate frequencies comprise GNSS intermediate frequencies, and the converted test signal is arranged to pass through the band-pass filter 116 of each of the signal paths.

For example, the converted test signal passes through the band-pass filters 116 (for each receive path), with center frequencies at f_IF. The BPFs 116 output the desired signals, e.g. at either +f_MOD (for GPS) or −f_MOD (for GLO) depending on the receive path, for example. The test signals are sampled by ADCs 118, and output to the baseband (BB) portion 202 of the communication device 100 for correlation.

In the example, as illustrated in FIG. 2, the digitized test signals are received at the BB 202, and the IF is wiped from the test signals at blocks 206 (using f_MOD, for example), in preparation for correlation. In an implementation, the BB 202 is arranged to detect a correlation peak with the knowledge of the applied code. In the implementation, one or more correlators 208 are arranged to analyze the converted test signal to determine an operational state of the communication device 100. For example, at the correlators 208, the received signals are correlated with codes (GPS and GLO, for this example) generated by the code generators 204. When the code generated by code generators 204 matches the code of the received signals, a peak is seen in the correlated signals generated by correlators 208.

FIGS. 5 and 6 are graphs showing a spectrum analysis of example correlator 208 output signals, associated with converted GPS test signals with amplitude modulation produced by on-off switching and by polarity switching, respectively, according to an implementation. The prominent correlator 208 peaks (502 and 602) are seen in the graphs, indicating a match in the GPS code generated by the code generator 204 to the GPS code of the received signals, for example. These peaks (e.g., 502, 602) are used by the baseband 202 to verify pass or failure of the self-test of the communication device 100.

Similar results may be achieved on the GLO receive path, when the GLO codes are used and the GLO test signal is processed (or any other CDMA codes and associated test signals), for example. When other types of CDMA test signals are processed (e.g., COMPASS, GALIEO, etc.) the corresponding satellite spreading codes can be arranged to be generated in the BB 202, at the code generators 204 for example, as described herein.

The output of the correlators 208 is processed by a processor, for example a combined microcontrol unit/digital signal processor (MCU/DSP) 210, or the like. The MCU/DSP 210 may be arranged to verify the pass or failure of the communication device 100 self-test, based on analyzing the correlator 208 outputs, for the peaks described. For example, the presence of the peak in the correlator 208 output indicates a pass of the self-test, and the absence of the peak in the correlator 208 output indicates a fail of the self-test. In alternate implementations, additional or other indicators may be used to verify pass or fail of the self-test.

The above described techniques and devices for self-testing a communication device 100 may be applied during production of the communication device 100 (for quality assurance, etc.) during normal operation, for example for regular self-tests, during scheduled and un-scheduled maintenance, and so forth.

It is to be understood that a communication device 100 may be implemented as a separate component or as part of a system including a communication device 100. The techniques and devices described herein with respect to a communication device 100 is not limited to the configurations shown in FIGS. 1-6, and may be applied to other configurations without departing from the scope of the disclosure. Various implementations of a communication device 100 as described herein, may include fewer components and remain within the scope of the disclosure. Alternately, other implementations of a communication device 100 may include additional components, or various combinations of the described components, and remain within the scope of the disclosure.

Representative Processes

FIG. 7 illustrates a representative process 700 of self-testing a communication device (such as communication device 100, for example) implemented as a system-on-chip (SoC), according to an implementation. The process 700 includes self-generating a test signal and self-analyzing a result of processing the test signal at the communication device. In an implementation, the communication device comprises a GNSS or other CDMA receiver. The process 700 is described with reference to FIGS. 1-6.

The order in which the process is described is not intended to be construed as a limitation, and any number of the described process blocks can be combined in any order to implement the process, or alternate processes. Additionally, individual blocks may be deleted from the process without departing from the spirit and scope of the subject matter described herein. Furthermore, the process can be implemented in any suitable hardware, software, firmware, or a combination thereof, without departing from the scope of the subject matter described herein.

At block 702, the process includes generating a radio frequency (RF) test signal at a receiver of a RF communication device having a single phase-locked loop (PLL) device (such as PLL device 104, for example). In an implementation, the process includes generating a local oscillator (LO) signal at the single PLL device of the RF communication device.

In an implementation, the process includes dividing a frequency of the LO signal by an integer value to produce a modulation frequency and modulating the LO signal at the modulation frequency to produce the test signal. In an implementation, the test signal has a center frequency at the frequency of the LO signal, and has first order frequency components at the frequency of the LO signal plus the modulation frequency and at the frequency of the LO signal less the modulation frequency.

In an implementation, the process includes spreading the test signal with a code sequence arranged to be decoded in a baseband portion of the receiver. In an example, the code sequence comprises a Code Division Multiple Access (CDMA) code sequence. For instance, the code sequence may include a global navigational satellite system (GNSS) code sequence, or the like. In implementations where the communication device does not include a CDMA feature, the process may be generalized (for non-CDMA receivers, etc) by omitting process elements comprising CDMA modulation and de-modulation in both signal generation and signal processing stages. In such implementations, the self-testing can be based on a sinusoidal-like test signal, or the like.

At block 704, the process includes processing the test signal with the receiver to test an operational state of the RF communication device. In an implementation, the process includes receiving and down converting the test signal to an intermediate frequency (IF) of the RF communication device. For example, the test signal may be converted at a front end portion (such as front end 114, for example) of the receiver. In the implementation, the process includes band-pass filtering the converted test signal, where the converted test signal passes a frequency band comprising the intermediate frequency plus the frequency of modulation and the intermediate frequency less the frequency of modulation.

In an implementation, the processing produces a resulting signal (such as the correlator 208 outputs 502 and 602, for example) at a baseband portion (such as baseband portion 202, for example) of the receiver.

At block 706, the process includes analyzing the resulting signal at the receiver (with the MCU/DSP 210, for example) to determine the operational state of the RF communication device. In an implementation, the output of the correlators is analyzed, as discussed above, to determine whether codes generated by the receiver (e.g., the code generators 204) match codes revealed in the test signal after processing. The output of the correlators may include indicators (such as the peaks 502 and 602, for example) of a code match, and thus a passing self-test. Indications of a failure to match the codes may also be an indication of a failing self-test, for example.

In an implementation, the process includes autonomously self-testing the operational state of the RF communication device during production of the RF communication device and during post-production of the RF communication device. In the implementation, the RF communication device is implemented with self-test functionality as a system on chip (SoC). In the implementation, the RF communication device is arranged to receive and to process GNSS signals.

In alternate implementations, other techniques may be included in the process in various combinations, and remain within the scope of the disclosure.

Conclusion

Although the implementations of the disclosure have been described in language specific to structural features and/or methodological acts, it is to be understood that the implementations are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as representative forms of implementing the invention. 

What is claimed is:
 1. A self-test apparatus, comprising: a radio frequency (RF) phase-locked loop (PLL) device arranged to generate a local oscillator (LO) signal; a divider component arranged to divide a frequency of the LO signal by an integer value to produce a modulation frequency; and a modulation component arranged to modulate the LO signal at the modulation frequency to produce a test signal arranged to test a system-on-chip (SoC) communication device that includes the self-test apparatus.
 2. The self-test apparatus of claim 1, wherein the communication device uses a single PLL device, comprising the RF PLL device.
 3. The self-test apparatus of claim 1, the modulation component further arranged to receive a code signal and to spread the test signal based on the code signal.
 4. The self-test apparatus, of claim 3, wherein the code signal comprises a Code Division Multiple Access (CDMA) code sequence and the spreaded test signal comprises a CDMA-type test signal arranged to be processed by a baseband portion of a CDMA receiver.
 5. The self-test apparatus of claim 1, the modulation component further arranged to modulate an amplitude the LO signal by switching the LO signal on and off or by switching a polarity of the LO signal at the modulation frequency.
 6. The self-test apparatus of claim 1, wherein the self-test apparatus comprises a radio frequency built-in self-test (RFBIST) mechanism of a SoC Global Navigation Satellite System (GNSS) communication device.
 7. A system-on-chip (SoC) implemented radio frequency (RF) communication device, comprising: a RF portion, including: a single radio frequency (RF) phase-locked loop (PLL) device arranged to generate a local oscillator (LO) signal; a divider component arranged to divide a frequency of the LO signal by an integer value to produce a modulation frequency; a modulation component arranged to modulate the LO signal at the modulation frequency to produce a test signal and to output the test signal, the test signal arranged to test the RF communication device; and a front end portion arranged to receive and to down-convert the test signal to form a converted test signal; and a baseband portion, including: one or more correlators arranged to analyze the converted test signal to determine an operational state of the RF communication device.
 8. The SoC implemented RF communication device of claim 7, wherein the RF portion further comprises one or more signal paths, each signal path including a band-pass filter tuned to one of a plurality of intermediate frequencies (IF) and an analog-to-digital converter (ADC) arranged to pass a digitized version of the converted test signal to the baseband portion.
 9. The SoC implemented RF communication device of claim 8, wherein the plurality of intermediate frequencies comprise a plurality of global navigational satellite system (GNSS) intermediate frequencies, and wherein the converted test signal is arranged to pass through the band-pass filter of each of the one or more signal paths.
 10. The SoC implemented RF communication device of claim 7, wherein the baseband portion further comprises a plurality of code generators arranged to generate and output code sequences to the modulation component, the code sequences representing one or more global navigational satellite system (GNSS) spreading codes.
 11. The SoC implemented RF communication device of claim 10, wherein the test signal is based on a fundamental frequency of the RF communication device, the test signal comprising the LO signal with amplitude modulation, and spreaded by a code division multiple access (CDMA) code.
 12. The SoC implemented RF communication device of claim 7, wherein the SoC-implemented RF communication device is arranged to autonomously self-generate the test signal at a receiver of the communication device, process the test signal through one or more receive signal paths of the RF communication device, and self-analyze test results of processing the test signal, to determine an operational state of the RF communication device.
 13. A method, comprising: generating a radio frequency (RF) test signal at a receiver of a RF communication device having a single phase-locked loop (PLL) device; processing the test signal with the receiver to test an operational state of the RF communication device, the processing producing a resulting signal at the receiver; and analyzing the resulting signal at the receiver to determine the operational state of the RF communication device.
 14. The method of claim 13, further comprising: generating a local oscillator (LO) signal at the single PLL device of the RF communication device; dividing a frequency of the LO signal by an integer value to produce a modulation frequency; and modulating the LO signal at the modulation frequency to produce the test signal.
 15. The method of claim 14, wherein the test signal has a center frequency at the frequency of the LO signal, and has first order frequency components at the frequency of the LO signal plus the modulation frequency and at the frequency of the LO signal less the modulation frequency.
 16. The method of claim 13, further comprising spreading the test signal with a code sequence arranged to be decoded in a baseband portion of the receiver.
 17. The method of claim 16, wherein the code sequence comprises a Code Division Multiple Access (CDMA) code sequence.
 18. The method of claim 13, further comprising receiving and down converting the test signal to an intermediate frequency (IF) of the RF communication device at a front end portion of the receiver and band-pass filtering the converted test signal, the converted test signal passing a frequency band comprising the intermediate frequency plus the frequency of modulation and the intermediate frequency less the frequency of modulation.
 19. The method of claim 13, further comprising autonomously self-testing the operational state of the RF communication device during production of the RF communication device and during post-production of the RF communication device, the RF communication device implemented with self-test functionality as a system on chip (SoC).
 20. The method of claim 13, wherein the RF communication device is arranged to receive and to process Global Navigation Satellite System (GNSS) signals. 